Knee Osteoarthritis is highly prevalent and results in significant disability. There is a need to develop interventions that can reduce disability and slow progression. Purpose. The studies in this text were aimed at understanding some of the factors that might be related to disability and progression in knee OA including quadriceps weakness, proprioceptive loss, altered stiffness and functional knee instability and their influence on function, joint loading during walking and neuromuscular adaptation to repeated perturbations. Methods. Quadriceps strength was measured isometrically at 90° flexion. Proprioception was assessed using threshold to detect passive motion and joint repositioning sense. Stiffness was measured as the torque vs position response to rapid 20° flexion during sitting. Functional knee instability was assessed using an item from Knee Outcome Survey-Activities of Daily Living Scale. Disability was assessed using Knee injury and Osteoarthritis Outcome Score and Stair Climbing Test. Joint loading during walking was estimated using an EMG-Driven musculoskeletal model. Neuromusucular adaptation to repeater perturbations was assessed by the EMG and kinematic response to valgus perturbations at initial contact during walking. Results and conclusion. Data show that proprioception and stiffness are not related to articular loading and neuromuscular adaptation. Quadriceps weakness and instability affects function poorly but does not affect joint loading and adaptation. It was also seen that people with knee OA have poor load sharing strategies and can adapt neuromuscular patterns similarly to control. This has important implications for rehabilitation.